Bed-reciprocating mechanism.



.H. PEARCE & F. SPENCE.

BED RECIPROCATING MECHANISM.

APPLICATIOA FILED AUGZZ. l9l6.

1 ,269, 1@, PatenwdJuno11, 1918.

rap snares rarnnr enrich w N n v HERBERT PEARCE AND FRED SPENCE, GE BROADHEATH, ENGLAND, AESSIGNURS T0 LINO'SYPE AND MACHINERY LIMITED, OF LONDON, ENGLAND.

BED-REGIPROCATIN'G MECHANISM.

Specification of Letters Patent. Patqgntgd J 11 1918 Original application filed May 12, 1915, Serial No. 27,506. Divided and this application filed August 22, 1916. Serial No. 116,362; 1

To all whom it may concern Be it known that we, HnnBnnrPnAncE and tion with, and is hereinafter dealt with as applied to, the beds of flat-bed printing presses, although it is to be understood that the invention may equally well be employed in connection with the reciprocation of the beds of planing and similar machines.

To secure the best results in a flat bed printing press, it is necessary that the bed travel through its printing and return strokes at a uniform velocity and that, at

the end of these strokes, and with as littlestrain'as possible, the bed be brought graduallyto a stop and have its direction of travel reversed and its velocity in the reverse direction gradually accelerated from the stop or zero up to themaxiinum. It is also of very great importance that for the slowing down, stopping and reversal of the bed, as small a proportion as possiblclot' the beds total travel be utilized, be- I cause the snialler that proportion, the greater will be the proportion available for printing, and consequently the greater will be the length (measured in the direction of the beds travel) of the surface which can be printed at each cycle of the press.

In the above-mentioned original application there is described a reversing device comprising a single crank pin to which are pivoted the meeting ends of two connecting rods Whose outer or opposite ends are pivotally connected each to a slide rectilinearly rceiprocated by the crank pin in a direction parallel with the movement of the bed, and devices including a single automatically operated latch for connecting the bed to, and disconnecting it from, the said slides in alternation near respectively opposite ends of the bcds travel, the arrangement being such that'the control of the bed is transferred from the normal bed-operatin gear which operates the bed at uniform've ocity during the actual printing stroke and the return stroke, to the crank pin, and again from the crank-pin to the normal bed-operating gear, at opposite ends of the travel of the This arrangement was designed so as to efl'ect each complete reversal within a period less than one half of that occupied by one rotation of the crank, and thereby to extend the travel of the bed. at uniform ve locity beyond the period occupied by one complete rotation of the bed driving pin.- ion, and it was shown to be essential, for this purpose, to have the connecting rods and crank of such relative lengths that, when the velocity of the respective slide in the direction of the beds travel is approximately equalto that ofthe bed, the equation 1- cos a L= sin b represents the length of the. connecting rod, 1' the radius of-the crank arm, a and b the angles formed "by the crank radius and connecting rod respectively with vertical and horizontal lines passing through the axis of rotation of the crank, and

a defining a position of the crank when the velocity of the slide is at or decreasing from are - a m3 of Wliicn 1s integral block or shcle a e device-A, A, or twomeinber hook a .J-l, A, and B, B, of the cation. The in V bees A subject-matter ofehe original eppiicmflion, but Without; the limitations 3' 11st referred ixo. Consequently, although invention is hereinafter for convenience described and illustrated in connection s machine (if the same general construction as that with in original maplieetion such no 50 be gerclec; in any restnct-i sense The invention will new be de cribed by reference to the eccotrn 1 ing drawings in "WlliCl13-- Figure l. is diagrammatic of certain organs of a list-ii of the above-named ccnstrucp.

Fig. 2 a diagram ill nslizi' governing the relelai l and connecting rods invention,

1 is ilie bed motion shaft; ii, the lie (i pinii which, through the reel: 12., serves propel he becl 11 at uniform oci bv clniin" die b l/ printing sfiroke, and which is in consent driving connection with the s 18, the bed, pinion il'lllC 20, serves propel the bi-x velocity during the res stroke, and which mew be c the same angular velocn.

'posiie (lirecsion to the sen.

seized by arrows in The crank pin a suitable crank, to pivoted on it the coi'ineciiing ITKlS 01" end of the 'i-ocis the stncls or pins 3 a m v sliding in sietionery sliown in ilie drawn allel with the mo Each of the slides e shown in tlieklmwing/ 'shey are rigidly eonnee respective slide 01? gar-(led as the eq'ziivs Eng hooks clescyibeci in bets in relatively ep'pesite say at the ouiel' entls oi: relmiively to the bed mom '1" F. q I I .10 K lie uinlei'sioe 01 me about the le. between the two pinions veisely to their common idly secured she lllaCl' which rigidly secures which is capable of ex inner VQE'ilCnl of the sic-re i when 5 e ceni'i'ol.

can be be transferred from the pinions i, 18,

c crank pin 30, that is to say, at those slants at which the reversing stud 89 and n: members A B, are traveling at equal velooil1 ,n {in the hanger 38 there are proviom l'vo latches l-O, es, Winch may be can Tili/m'ly n'zevablc as 's 'zlie single latch in i'olein guii'les 51 shown in l,

l i'cspeciively nclapleo to cmxhe ineinliey A en. the Sl1 i6 35 and the 'n oer I on the sncle 36 in such manner particular n'ieinoei OX "speo'mveletch 1s ,ioi' the inerespeciive roller and allow 0:123? to pass above or below it, 1 inc evnnnole illustrated, the roller latch il) passes unobssrnctedly 'e c cam race and. is engegecl by the c m race i3, and lie roller 411 of the latch pus es unobstrucieclly under the cam race is engaged by the cam race -19. any lemme being caused by 1'81? allure of the respective spring to latch 1-0 or 40 in its highest poslop 46, a Temp is pro- L e inner end of each cam race,

' m guide the respective higher portions of the e m-iginel application, or rcctilinesrly i) ll suitable 'means moved laterally to bring the former (4) into a position in which it will subsequently be engaged by the rack 12 during the next ensuing or already started printing stroke, and the latter (18) out of.

the path which will be pursued by the. rack 20 during that stroke. At the conclusion of the just-mentioned. l80-2a degrees angular motion of the crank pin 30 the slide 35 and bed lthave again attained the velocity of i the uniform travel of the latter, and the bed pinion 4 runs into mesh with the rack 12. Immediately thereafter the latch 40 is moved rectilinearly in the guides 51, by the action of the cam race 42 on its roller 41, out of engagement with the hook-member A, and the stud 39 also moves out of contact with the hook member A by reason or the now slowexili/rzozement of the latter, and the bed 11 co inues its printing stroke under the solecontrol of the pinion 4 and rack 12, the latch 40, when it has run beyond the control of the cam race 42, being meanwhile maintained by its spring in its raised position against the respective stop 46.

- As the-"bed 11 approaches the end of its printing stroke, that is to say, at or about the instant at which the pinion 4 completes the next 360+2a degrees of angular motion, the bed rack 12 runs out of mesh with the 'pinion 4, and the slide 36 is traveling at the same velocity as the bed. At or about that instant the reversing stud 39 abuts against the hook-mcmbcr B on the slide 36 and the roller 41 of the latch 40, which had by that time already been depressed by passing along the descending portion of the cam race 43, completes the engagement of that latch with the hook B, B, thus, for the time being, locking the bed 11 to, and placing it under the control of the crank pin 30. The slowing down, stopping, reversing and spcedirig'up of the bed now take place during the next ensuing angular motion of say 180-214 degrees of the crank pin 30, just as though the said crank pin were in pcrmanent operative connection with that bed, and at any part of the time occupied by the just-named angular movement of the crank pin, the bed pinions 1S and 4, are again moved laterally, to bring the Former (18) into a position in which it will subsequently be engaged by tile rack 20 during the next ensuing or already started non-printing stroke, and the latter (4) out of the path which will be'iursued by the rack 12 during that stroke. lit the completion of the justmentioned angular motion of 180-244 de grees of the crank pin 30, the hook B, B, is again traveling at the same velocity as is the bed 11. At that juncture the bed rack 20 runs into mesh with and is operatively engaged by the pinion l8, and the mutual separation of the stud 39, hook B, B, and latch 40 commences, the latch being raised clear of the hook B, B, bythe ascending part of the cam race 43, in the same manner as the latch 40 was previously raised by the cam race -12 at the commencement of the printing stroke.

The bed 11 is then traverse-d through its non-printing stroke at uniform velocity by the rack 20 and pinion 18,and at ,or about the instant at which the pinion 18 completes say 360+2a degrees of angular motion from the position atwhich the bed started the portion of its non-printing stroke of uniform velocity, the parts again assume the position indicated in Fig. 1.

The use of two latches separated by an' interval of distance, in' accordance with the present invention, for effecting the reversal at respectively opposite ends of the beds travel, instead of, as in the original appli cation, a single latch for effecting the re versal at both ends of the beds travel, allows a considerable variation of the lengths of the connecting rods as compared with those in the last-mentioned arrangement, and eliminates as a factor determining such length, the length of travel of the bed at uniform velocity.

In the present case, the length of the two connecting, rods can be of any predetermined valuo, provided that the/conditions hereinafter set forth are satisfied, and not necessarily of equal values, these latter depending upon the distanceat which the respcctivc latches are, in the direction of travel of the bed, spaced from the mid position which would be occupied by a single latch, were such used.

In the application of the mechanism according to the present invention to the reversal of a printing press, it is obvious that the respective slide 35 or 36 can besatisfactorily engaged with the bed only at that instant at which it is moving in the same direction as the bed, and at the same or approximately the same velocity as that of the bed, and, when a so-callcd reversing stud 3!) is employed the velocity of the slide at such instants must be at its maxinuuu; It the reversing stud be dispensed with, the

lasfuianacd restriction would not, however,

chosen so that the immediately subsequent;

FEE.

velocity of the siicic docs can; increase. prccisc ccnditions governing the reiaiioir ship between the lengths of thc ccnncfing rod and crank radius necessary tc SP4 angular vcioci y, 11m let V: Ac 1i velocity of the crank pm, then, accord to WcH. known construction velocity of thc'siidc L113 a" of Fig. 2 reprcsc-"fi to' some icciily V f the cm 1; min 30 position of the crank pm let the iinc cminccting rod 31, producer." i1 require i 2 intcrscct "iiic vcriica? -21 01 the bcci m1; icin s t 1) it :1 {3972A} which the cci'mccting' than the lcngci In will icpicsclxfi we vc ig ill 1 iccity of the slide t0 sail c sczzic ,953 (5 d that at which the radius 9" rcpicscnts hc vcicmty oi. the crank pin The vcicm 1? 0f the bail will be that Of the pii'ch iine of 1 v driving pinion m wimievfil 5 Thc izis'iw-ifmmcd condition in which a is RdlillS may be, sincc (hr-Ru rm. ins is meving assumcti to equal I) is that in. which, as pre- With the same a g l velocity 70651 vkmsiy stat 0. the mnxinzum vciocity of the equal to the RUFF-(121i c maxinmm driving pinion, at he pcsition or instant of g, Q ,cngagemcnt between the slide and the bcci, i it f {h 5 U i 1 1 g the intercept 1K must be equal $0 the pit h that when izhc velocity thc Slide 35 is at Zinc rad us of the i i011. its nmximwm ihcn acceicmticii is zcrcfi 30 T119 2?? i i 'fl ijflhg liflflii; pin 30 thic conpiitioii is the MP to cmplcy. -fli"i 95 and thc position 0% the 511016 as m which 5' lgng'th L 1 th nn mm 7395i 31 i y velocity is a n'mximum can be dci'crmincci B 1 igjg'gllninud 4,; if; i'cizition L siiii by a tedious caicuizi sion, but suiiicieiitiy Z ::;-*cc$mi1cnce close approximation is that which assumes 1 a 55 'jic E'QiGCIi j' of th slide 10 be in; its maxii- 109 mum when the conncccing' rod 31 and crank M I P 7 1 w radius a are at mghj; zvngies with each 0151mm vibe was; pilnciplc 031' me ccd-opcm'mng w kw E; 1 t (31.1), .L Let E radms of pitch line of bed din 111s; Ji 5gb j 30mm prcscm HsVQ'QiiIOD may be said m'vclvc A n w M i. w LN aznii 'ic of ci'nnlrmdins 1 \vi f" 1 "Miami minim m mlfiung kmi i A j i 1 9 nqqumw .{Oihbf 0s a W ly sucn, as 2% slice 30 produced.

assing its axis of ro'tzifiicil, when rctardzlticn is to begin, Let 9":radius 0i cmni: arm, Let c hmizcnmi distance of fi'om i'hc vcrficai iin the axis of mmtion of at the instant of cnq-ug cm with the bevL bcingci an;

51111 A i'i a ccnnccting rod and i'ctating crank, 'miicil cf such moticn fci c'ficcfi rcctiiimcariy' cricd. iulicn 11G d .cciipicd by n'icniioncd sumeci lcngfih 5 half the aimvci c" T150121"; wfggi y q distance i 2% r Lei g c 0f conncc rcci with h u a a of rotation of the gi'zmk, and

Then, taking a ca in which ing pinion rota. Uhrough fcr the travel of the bed at uni:

the original appiica'iiioni iisfiancc mcvc it:

-g 1 L a: Low '1 i; cpposuic i :3 y zigcwici 50 mm 13c crank.

about the axis common to both pinions, two connecting rods, two slides each connected to the crank by one of the said rods and adapted to be reciprocated thereby at velocities varying downwardly to and upwardly from zero, a two-member hook fast to each of the. two slides, a stud rigid with the bed and adapted, by reason of the relative motion of the bed and slide, to engage with and disengage from one member of each of the said hooks in alternation, two latches adapted to move independently of the bed but accompanying it throughout its travel, means adapted to automatically effect the engagement of one of the said latches with and its disengagement from the other member 01 one of the said hooks near one end of the travel of the bed, and means adapted to automatically effect the engagement of the other of the said latches with and its disengagement from the corresponding member of the other hook near the respectively opposite end of the travel of the bed, the respective engagements and disengagements of the stud and latches with and from the hooks being effected at instants at which the velocity of the respective slide is equal or approximately equal to that of; the bed, an within a period which is l' ss than one hal of that occupzled by on revolutionofythe 2. In bed-reciprocating. mechanism, the combination with a reciprocating bed and two spur pinions adapted to move the bed at uniform velocity in respectively opposite direntions, oi aicrank adapted to rotate at the same angular velocity as the said ninions, two connecting rods, two slides each connected to the crank by one of the said rods and adapted to be reciprocated thereby at velocities varying'downwardly to and upwardly from zero, a two-member hook fast to each of the two slides, a stud rigid with the bed and adapted, by reasonof the relative motion of the with and disengage from one member of each of the said hooks in alternation, two latches adapted to move independently of the bed but accompanying it throughout its travel, means. adapted to automatically effect the engagement of one of said latches with and its ise gagement from the other member of on of the said hooks near one end of the travel of the bed, and means adapted to automatically efiect the engagement of the other of the said latches with.

and its disengagement from the corresponding member of the other hook near the respectively opposite end'of the travel of the bed, the respective engagements and disengagement's' of the stud and latches with and from the hooks being effected at instants at which is equal or approximately equal to that of the bed and within a period which is less than one half of thatoccupied by one revolution of the crank.

bed and slide, to engage" the velocity of the respective slide 7 In witness whereof we have hereunto set .our hands in the IpIresent-e of two witnesses.

ERBERT PEARCE. FRED SPENCE. Witnesses:

Fnn'o WESLEY WRIGHT, Josnrn LAMB. 

